How do you mean, "don't function", do not light? do not spark?. the burner head, 2 parts lift off, top disk, and the surround disk. After that, except for spark elecrode, the big hole goes back to the control knob at the front, You would have to remove the top to get to them, starts with about 5 screws along the back edge, but cannot see it being that, unless control valve faulty, mechanical valve so should not think so. Model number etc, you will find in the draw unit, bottom rht, pull draw forward lift it pull out, plate is on lft side. But model, is Rangemaster 110
SD, April 2012